Util.java

package guang.crawler.siteManager.util;

/**
 * 一些实用类.是从Crawler4J中截取过来的.我也没有看过.
 * 
 * @author sun
 *
 */
public class Util {
	
	public static int byteArray2Int(final byte[] b) {
		int value = 0;
		for (int i = 0; i < 4; i++) {
			int shift = (4 - 1 - i) * 8;
			value += (b[i] & 0x000000FF) << shift;
		}
		return value;
	}
	
	public static long byteArray2Long(final byte[] b) {
		int value = 0;
		for (int i = 0; i < 8; i++) {
			int shift = (8 - 1 - i) * 8;
			value += (b[i] & 0x000000FF) << shift;
		}
		return value;
	}
	
	/**
	 * 对一些被认定为二进制文件的内容
	 */
	public static boolean hasBinaryContent(final String contentType) {
		if (contentType != null) {
			String typeStr = contentType.toLowerCase();
			if (typeStr.contains("image") || typeStr.contains("audio")
			        || typeStr.contains("video")
			        || typeStr.contains("application")) {
				return true;
			}
		}
		return false;
	}
	
	public static boolean hasPlainTextContent(final String contentType) {
		if (contentType != null) {
			String typeStr = contentType.toLowerCase();
			if (typeStr.contains("text/plain")) {
				return true;
			}
		}
		return false;
	}
	
	public static byte[] int2ByteArray(final int value) {
		byte[] b = new byte[4];
		for (int i = 0; i < 4; i++) {
			int offset = (3 - i) * 8;
			b[i] = (byte) ((value >>> offset) & 0xFF);
		}
		return b;
	}
	
	public static byte[] long2ByteArray(final long l) {
		byte[] array = new byte[8];
		int i, shift;
		for (i = 0, shift = 56; i < 8; i++, shift -= 8) {
			array[i] = (byte) (0xFF & (l >> shift));
		}
		return array;
	}
	
	public static void putIntInByteArray(final int value, final byte[] buf,
	        final int offset) {
		for (int i = 0; i < 4; i++) {
			int valueOffset = (3 - i) * 8;
			buf[offset + i] = (byte) ((value >>> valueOffset) & 0xFF);
		}
	}
}